During the first stage of triaxial test when the cell pressure is increased from 0.10 N/mm2 to 0.26 N/mm2, the pore water pressure increases from 0.07 N/mm2 to 0.15 “N/mm2. Skempton’s pore pressure parameter B is___________________?
A. 0.5
B. -0.5
C. 2.0
D. – 2.0